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What is Cystic Fibrosis?
Cystic fibrosis (CF) is a genetic disease affecting approximately 30,000
children and adults in the United States. Around 1,000 new cases of CF are
diagnosed each year. CF occurs in one of every 3,200 live Caucasian births
and in one of every 15,000 African-American births. CF is less common in
Asians and Native Americans, but is being seen more often in Hispanics. More
than 80 percent of patients are diagnosed by age three; however, almost 10
percent of new diagnoses are age 18 or older. About 3 % of patients with CF
are diagnosed in adulthood
In CF, mucus glands do not secrete normal, free-flowing fluid. Instead, a
defective gene causes the body to produce abnormally thick, sticky mucus,
which blocks ducts and other passageways in the body, particularly in the
lungs and intestines interfering with vital functions such as breathing and
digestion. In the lungs, these thick secretions clog airways leading to
recurrent infections. Thick secretions also obstruct the pancreas,
preventing digestion and absorption of fats and fat-soluble vitamins,
leading to nutrition deficiencies and intestinal complications.
According to the CF Foundation's National Patient Registry, the median
age of survival for a person with CF is 35 years. As more advances have been
made in the treatment of CF, the number of patients with CF living into
adulthood has steadily grown. Today, nearly 40 percent of the CF population
is age 18 and older. Adults may experience additional health challenges
including CF-related diabetes and osteoporosis.
Cystic Fibrosis is currently incurable. Ten years ago, the life
expectancy of a person with CF was an average of 18 years. Advances in
research and treatment have helped extend median survival to greater than 33
years. Early diagnosis, aggressive therapy, continued research, and routine
check-ups are essential to patient health. With proper care, many patients
with CF are living into adulthood and leading normal, productive lives.
•
How Do You Get CF?
•
Symptoms and Complications
• Diagnosis
• Treatment
How Do You Get CF?
Cystic Fibrosis is not contagious. It is a genetic or inherited disease,
beginning at conception from a defect or abnormality of a gene. More than 10
million Americans are unknowing, symptom-free carriers of the defective CF
gene. An individual must inherit two defective CF genes -- one from each
parent -- to have CF. Each time two carriers conceive, there is a 25 percent
chance that their child will have CF; a 50 percent chance that the child
will be a carrier of the CF gene; and a 25 percent chance that the child
will be a non-carrier.
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Symptoms and Complications
Symptoms vary from person to person due to the fact that more than 1,000
mutations of the CF gene exist. CF symptoms develop during the first years
of life of most patients, although they may not be obvious in young children
and blamed initially on other causes. In approximately 10-15% of the cases,
the earliest symptom of CF appears at birth in the form intestinal blockage,
called meconium ileus, which usually requires surgical removal. The lungs
and pancreas produce the most common symptoms, usually respiratory and
gastrointestinal complications. The lesser symptoms involve the reproductive
tract and sweat glands.
•
Respiratory
•
Gastrointestinal
•
Reproductive
• Sweat
glands
Respiratory
At some time in their lives, patients with CF develop lung disease. The
thick mucus produced in CF blocks the airways interfering with normal
breathing and eventually leading to lung damage. Respiratory symptoms
include recurrent infections such as chronic cough, wheezing, shortness of
breath, pneumonia,
bronchitis, bronchiectasis;
pneumothorax; hemoptysis;
digital clubbing;
cor pulmonale; sinusitis;
nasal polyps; and
allergic
bronchopulmonary aspergillosis. Your physician and health team will
assist you in creating a respiratory treatment plan to help keep your
lungs healthy and prevent lung damage.
Pneumonia - lung infection with
consolidation, which can be caused by a number of organisms. Patients
with CF are at risk for infections as the abnormal mucus and reduced
water content in the airways enhances growth of bacteria.
Bronchitis - inflammation and
swelling in the airways leads to obstruction and triggers mucus
production, which increases chances of infection.
Bronchiectasis – chronic,
recurrent respiratory infections lead to permanent lung damage, which is
the leading cause of mortality in CF patients. Bronchiectasis is the
chronic dilation of the airways allowing them to be filled with mucus,
leading to infection, which leads to even more damage.
Pneumothorax – accumulation of air
or gas between the lung and chest wall that can occur as a result of
trauma or a disease process. Approximately 10% of patients with CF
experience a pneumothorax.
Hemoptysis – coughing up blood or
blood stained mucus
Digital clubbing – enlarged,
rounded, shiny appearance in skin at the ends of fingers and toes
(usually in advanced disease)
Cor pulmonale – enlargement of
right side of heart caused by high resistance to blood flow in lungs
Sinusitis – swelling and inflammation
in the mucosa of the sinuses leading to runny nose and nasal obstruction
Nasal polyps – protruding, fleshy
growths from the nasal mucosal membrane. Occurs in 15-20% of patients
with CF and often requires surgery
Allergic
bronchopulmonary aspergillosis - a fungal infection in the lungs
of Aspergillus.
Return to Symptoms and
Complications
Gastrointestinal
The pancreas and other organs of the digestive system secrete enzymes
into the intestine where they help to break down food, which the body uses
for energy, growth, and maintenance. In CF thick, sticky mucus blocks the
passageways that carry these enzymes to the intestines. This results in
poor digestion and the food eaten cannot be used by the body. Because of
the increased metabolic demands on the body by the respiratory disease,
added with malabsorption of the food, the individual with CF often has a
large appetite, but still may appear under nourished. Symptoms of
pancreatic insufficiency are found in 90% of patients with CF. These
include an excessive appetite but poor weight gain; and greasy, bulky,
foul smelling stools; meconuim ileus;
distal intestinal obstruction;
gastroesophageal reflux;
hyperglycemia; abdominal discomfort;
liver disease; and
rectal prolapse.
Meconium ileus – meconium refers
to a newborn’s first stool, which is thick, sticky, dark green, and
odorless. Ileus refers to an obstruction in the intestine. In babies
with meconium ileus, the bowel is blocked with very thick meconium
prohibiting passing of stool. This occurs in approximately 10-15% of
newborns with CF.
Distal intestinal
obstruction – similar to meconium ileus, it is a syndrome
occurring in children and young adults with CF. It results from
improperly digested fats and proteins, which form a mass and block
intestines. Symptoms include right lower side pain, loss of appetite,
and vomiting.
Gastroesophageal reflux
– a backward flow of stomach contents in the esophagus
Hyperglycemia – high blood sugar
resulting from insufficient insulin. The pancreas is responsible for
producing insulin, which converts sugar (glucose) into energy. A small
percentage of patients with CF will have diabetes, but it usually
doesn’t appear until 20-30 years of age. Symptoms that might occur are
thirst, dry mouth, and frequent urination.
Liver disease (cirrhosis) – liver
complications include a fatty liver; biliary fibrosis caused by blocked
bile ducts leading to inflammation, leading to fibrosis, leading to
development of gallstones.
Rectal prolapse – lining of
rectum protrudes out the anus.
Return to Symptoms and
Complications
Reproductive
Reproductive tract complications include delayed puberty in both male
and female patients with CF. This is thought to be due to nutritional
inadequacies. Most males with CF (more than 95%) are
azoospermic due an absence of the vas deferens
(tube which carries sperm from testis to urethra) making them sterile, but
with new technologies some are becoming fathers. Sexual function is not
impaired. About 20% of females are infertile due to effects of chronic
lung disease on menstrual cycle and thick mucus on cervix impedes movement
of sperm. If a woman wants to get pregnant, she should know the risks.
Limited lung function and other health factors may make it difficult to
carry a child to term. The added demands of childcare and how it will
effect personal health should also be considered. CF alone is not a method
of birth control. Sexually active patients should discuss birth control
options with their physician. Some antibiotics make oral contraceptives
less effective. Some patients may also have liver disease or diabetes that
should be considered. Safe sex and protection from STD is vital for all.
Azoospermic – absence of sperm
Return to Symptoms and
Complications
Sweat glands
The effect of CF on the sweat glands results in a high concentration of
salt in perspiration. This is due to the abnormal transport of chloride
across the cell membrane. During periods of increased sweating, such as
during exercise, elevated temperature, or hot weather, this salt loss can
but patient at risk for heat exhaustion and dehydration.
Return to Symptoms and
Complications
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Diagnosis
The sweat test is the number one diagnostic test for CF. It is the
simplest and most reliable method of diagnosing CF by determining an
abnormally high salt content in the sweat. It involves using a chemical and
a mild electric current to stimulate skin to sweat, wrapping the stimulated
area with plastic and a pad to absorb the sweat, and collecting the sweat
for analysis after 45 minutes-1 hour. A concentration of chloride greater
than 60 mmol per litre is a positive indication for CF. A sweat test should
be performed at a CF Foundation-accredited care center where strict
guidelines are followed to ensure accurate results.
Medical history is essential in diagnosing CF, as several symptoms will
provide a physician with important clues. Because CF is an inherited
disorder, a family history of CF might also suggest the gene might be
present.
A genetic test, also called a genotype or mutation analysis, can analyze
DNA for presence of one of the several hundred mutations that can cause CF.
This test involves collecting a blood sample. This test cannot detect all of
the mutations that cause CF, so reliability is around 85%.
Other less common forms of diagnostic testing include Immunoreactive
Trypsinogen Test (IRT) and Nasal Potential Difference (NPD) measurement.
IRT may be performed in newborns who can’t produce enough sweat for the
sweat test. This is a blood test that evaluates the presence of the protein
trypsinogen. If the test is positive, it should be confirmed by a mutation
analysis. The combination of these two test is sensitive to 90%-100%. With
NPD, a surface electrode measures the electric potential difference (the
amount of energy required to move an electrical charge from one point to
another) as the Na+ (sodium) and Cl- (chloride) ions move across the cell
membranes in the lining of the nasal passages.
Prenatal genetic testing can be performed to determine if the unborn
child has CF, although this test is not foolproof. Amniocentesis involves
removing cells from the amniotic fluid surrounding the fetus. Chorionic
villus biopsy involves sampling tissue that develops into the placenta.
Because prenatal genetic screening is expensive and carries some risk to the
mother, not all women who are CF carriers choose to have these tests.
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Treatment
Since there is no cure for CF, many different kinds of therapy have been
developed to decrease the progression of the disease. The treatment of CF
depends upon the stage of the disease and the organs involved. Both
symptomatic and preventative treatment is important to fight active
infections and maintain pulmonary health. Your healthcare team will assist
in developing a treatment plan that is right for you.
•
Respiratory treatment
•
Gastrointestinal treatment
• Exercise
Respiratory treatment
Clearing mucus from the lungs is an important part of the daily CF
treatment regimen since lung involvement accounts for most of the
morbidity and mortality. Thick secretions hinder the method that normally
moves mucus out of the lungs (the mucocilliary escalator). If these
secretions are not cleared, they can block the airways. The mucus also
provides an ideal place for bacteria to grow and multiply resulting in
chronic lung infections. Chest physical therapy (CPT) is a form of airway
clearance done by vigorous clapping on the back and chest using drainage
positions to dislodge the thick mucus from the lungs. 3-5 minutes of
clapping over specific areas of the chest combined with drainage positions
is essential. Comfortable attire should be worn such as a soft T-shirt.
Avoid clapping over buttons and seams. A CPT treatment takes approximately
30-45 minutes. CPT should be performed before meals or at least an hour
after a meal. A respiratory therapist will provide you with written and
verbal instruction on proper technique as well as demonstration and
adherence tips. How often CPT is performed daily will depend on each
patient’s individual health.
Alternative methods of airway clearance exist, but depend on age and
size of patient, cooperation, and technique. Once a patient reaches age of
2 years and a chest circumference of 20-23 inches, the physician may
introduce the The Vest
system to replace CPT. The Vest
system works by high-frequency oscillation of chest wall to remove
secretions. A respiratory therapist will provide you with information on
the proper settings and technique of performing The Vest
therapy as well as
order of inhaled medications used in conjunction with The Vest
therapy. Older patients
(5 years and up) may be able to perform
PEP
therapy. PEP works by having patient exhale through a restricted opening
creating a build up of backpressure in the lungs. This pressure results in
the expansion of the small airways and opens side channels to get behind
mucus and move secretions forward to the large airways where they can be
coughed out. The patient will perform active cough maneuvers to remove
secretions. Some PEP devices have a vibration capability, such as the
Acapella
or
Flutter. This vibration furthers mucus clearance. The key to PEP
therapy is proper technique otherwise, treatment is not effective. A
respiratory therapist will provide instruction on proper technique. PEP
therapy is usually used as an adjunct to CPT or The Vest
therapy, instead of a
replacement therapy. Most PEP devices are small making device an
alternative to take on trips, camp, school, or vacation. Another device
that may be used in the hospital is called an
Intrapulmonary Percussive Ventilator (IPV). IPV works using percussive
bursts of air to maintain a pressure wedge while high speed flows open
airways and enhance secretion mobilization. These prolonged percussive
intervals will expand the lung, mobilize secretions, and deliver
aerosolized medications to the peripheral airways. There are IPV machines
available for home use, but these expensive devices are not covered by
most insurance policies.
Aerosol therapy will be another part of the daily regimen. The purpose
of aerosol therapy is to deliver a fine mist of medication into the lungs.
Necessary equipment includes a compressor, which blows air into a
nebulizer or “cup” changing liquid medicine into a mist. Aerosol
treatments are given to infants with a mask and are given with mouthpiece
to older children (6 years and up). A respiratory therapist will help
demonstrate how to administer different aerosol medications and provide
the proper equipment. There are several different aerosol medications
prescribed for a patient with CF. The most common is Albuterol, a
bronchodilator that helps open the airways. Albuterol is given prior to or
during CPT to aid in secretion clearance. Other types of inhaled
medication include Pulmozyme®, a
mucus-thinning drug shown to reduce the number of lung infections and
improve lung function, can be given prior to CPT or during The Vest
therapy;
TOBI® (tobramycin solution for
inhalation), an aerosolized antibiotic used to treat lung infections
should be given after airway clearance therapy; inhaled corticosteroids (Pulmicort
Respules, Flovent, Advair), to reduce inflammation and swelling in tissues
of airways, should be given after airway clearance and before TOBI®.
Return to Treatment
Gastrointestinal treatment
Dietary management is important for each patient with CF the goal being
to provide enough nutrition ( webmaster - link to nutrition on main page
for more information) for maximum growth. This means a balanced diet of
high calories, protein, other nutrients, enzymes, and vitamin supplements.
A nutritionist will help create a dietary management plan. Sometimes
patients cannot eat enough calories in their regular diet to maintain or
gain weight. Milkshakes and high-calorie nutritional supplements that come
in ready-to-drink preparation, powders to mix as a drink, or sprinkle on
food can be prescribed. A few individuals may not be able to take in
enough calories orally to maintain or gain weight. In these special cases,
calories in the form of a liquid formula can be given to a patient by a
feeding tube directly into the stomach or intestine overnight while they
sleep. These feeding tubes can be placed in a number of different ways. A
nasogastric tube (NG-tube) is inserted nightly through the nose, down the
throat, and into the stomach. A gastrostomy tube (G-tube) is surgically
placed through the skin in the upper abdomen and into the stomach. A
Jejunostomy (J-tube) is similar to gastrostomy except tube is inserted
into part of intestine instead of stomach protecting against reflux. The
idea of a “tube” of any sort is scary at first, but the dramatic growth
results will win out. Many patients and families feel relief when they
don’t have to fuss and fight about eating or feel they now have to force
themselves to eat so much. Your physician will help decide what is best
for you.
Mucus blocks the tiny tubes in the pancreas of people with CF meaning
the pancreatic digestive enzymes are not secreted into the intestine.
These enzymes are responsible for breaking down fat, starch, and protein
that can then be absorbed. 90% of all CF patients benefit from pancreatic
enzyme replacement therapy (PERT). The adequacy of pancreatic function can
be evaluated by inspecting the stools for greasiness, frothy appearance,
foul odor, bulkiness, or by laboratory test calculating fat in stools
(fecal fat study). Enzymes should be given prior to each meal and snack.
Enzyme preparation and dosage will be determined for each patient based on
diet, weight gain, and bowel movements. Dosage will need to be readjusted
periodically as patient grows. There are different brands of enzymes
including Ultrase,
Creon,
Pancreacarb, pancrease,
and cotazyme. Your nutritionist and physician will assist in selecting
your pancreatic enzyme replacement therapy.
Enzymes work best in an alkaline environment, so sometimes even when
they reach the intestines the effects are reduced by the high acid
content. H2 blockers are a type of drug that helps reduce the stomach
acid. They are prescribed for some patients with CF in efforts to create a
more alkaline environment so the pancreatic enzymes can do their job. They
also can help break up clumps of undigested food that lead to distal
intestinal obstruction.
Vitamins A, D, E, and K require fat to be absorbed. Since CF patients
have difficulty digesting and absorbing fat, these vitamin levels are
often low. Patients will be placed on daily vitamin supplements based on
age. This dose is higher than that recommended for persons without CF. To
make vitamins easier to absorb, they can be taken with meals when enzymes
are supplied. Care should be taken not to leave vitamins and enzymes in
the car as the heat can break down medication and make it less effective.
Store in a cool environment.
Return to Treatment
Exercise
Exercise and physical fitness are important in maintaining muscle
strength, endurance, flexibility, and general good health. Exercise should
be encouraged in children and young adults with cystic fibrosis as regular
exercise will help clear mucus from the lungs, build up respiratory
muscles, and improve ability to breathe. We recommend consistent aerobic
activity for 30-60 minutes a day, to be added in addition to airway
clearance therapy. This can be in the form of running, jumping rope,
swimming, or dancing. Extracurricular activity in various sports should be
encouraged. Just remember to drink plenty of fluid to prevent dehydration
and boost calories to prevent weight loss.
Return to Treatment
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University of Arkansas for Medical Sciences
Department of Pediatrics
Section of Pediatric Pulmonology
Arkansas Children's Hospital
800 Marshall Street
Little Rock, AR 72202
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